The US State Department said Washington had been in touch with Yemen's President Abedrabbo Mansour Hadi as late as Wednesday but was not able to say where he is.
"We were in touch with him earlier today," spokeswoman Jen Psaki told reporters.
"He is no longer at his residence, which you've seen in reporting ... I am not in a position to confirm any additional details from here about his location. We have been in touch with him over the last several days."